摘要:
This invention offers a signal processing circuit of an electrostatic capacity type touch panel which is capable of switching between a differential input mode and a single input mode and has an extended adjustable range of an offset in the single input mode. The signal processing circuit of this invention includes a first sensor circuit of a differential input type, a second sensor circuit of a single input type, a third and fourth electrostatic capacitors that are variable capacitors for calibration to adjust the offset in an output voltage of the first sensor circuit, and a switching control circuit to control so as to put in operation one of the first and second sensor circuits. The switching control circuit also controls so that the third and fourth electrostatic capacitors for calibration are connected in parallel to each other when the second sensor circuit is put in operation.
摘要:
The invention realizes certainly detecting two or more positions on a touch panel that are touched at the same time. A drive circuit selects one from X lines, and supplies an alternating drive voltage to the selected line. A multiplexer selects a first sense line and a second sense line from Y lines that extend to cross the X lines. A charge amplifier outputs an output voltage corresponding to a difference between a first capacitance between the first sense line and the X line selected by the drive circuit and a second capacitance between the second sense line and the X line selected by the drive circuit. A touch position is then detected based on the output voltage of the charge amplifier.
摘要:
A conventional inverting amplifier has a problem that an oscillation may be induced depending on a structure of an internal amplifier. This invention offers an inverting amplifier having a multi-stage amplifier that is provided with a first transistor that amplifies an input signal, a second transistor that amplifies an output signal of the first transistor, a third transistor that amplifies an output signal of the second transistor and an internal feedback resistor that feeds back an output signal of the third transistor to an output node of the first transistor. With the structure described above, a required gain can be set without inducing oscillation, because a gain of the multi-stage amplifier composed of three-stage transistors can be reduced.
摘要:
There is offered a signal processing device of touch panel using an electrostatic capacity, which realizes improvement in noise tolerance and linear detection. An excitation pad, a first touch pad and a second touch pad are disposed on a substrate in a way that the excitation pad is interposed between the first and second touch pads. On the other hand, an alternating current power supply that provides the excitation pad with an alternating voltage through a wiring is provided on a sensor IC side of the signal processing device of touch panel. Also, there is provided an electric charge amplifier. The first touch pad is connected to a non-inverting input terminal (+) of the electric charge amplifier through an wiring, while the second touch pad is connected to an inverting input terminal (−) of the electric charge amplifier through a wiring.
摘要:
There is offered a signal processing circuit of the electrostatic capacity type touch panel which can eliminate duplication of components to reduce a cost of the components. A touch panel 51 is formed on a glass substrate 200. Sensor circuits 50A and 50B are arrayed in a Y direction, and sensor circuits 50C and 50D are arrayed in an X direction on the periphery of the touch pane 51. Serial clock terminals SCL of the sensor circuits 50A-50D are connected to a serial clock line 53 all together, while serial data terminals SDA are connected to a serial data line 54 all together. A microcomputer 52 is disposed on a PCB substrate outside the glass substrate 200. Data communication can be performed between the microcomputer 52 and the sensor circuits 50A-50D through the serial clock line 53 and the serial data line 54.
摘要:
There is offered a signal processing device of touch panel using an electrostatic capacity, which realizes improvement in noise tolerance and linear detection. An excitation pad, a first touch pad and a second touch pad are disposed on a substrate in a way that the excitation pad is interposed between the first and second touch pads. On the other hand, an alternating current power supply that provides the excitation pad with an alternating voltage through a wiring is provided on a sensor IC side of the signal processing device of touch panel. Also, there is provided an electric charge amplifier. The first touch pad is connected to a non-inverting input terminal (+) of the electric charge amplifier through an wiring, while the second touch pad is connected to an inverting input terminal (−) of the electric charge amplifier through a wiring.
摘要:
A signal detection circuit of a magnetic sensor includes a differential amplifier to which an output voltage of a detecting coil of the magnetic sensor is applied; a comparator to which the output of the differential amplifier is input, the comparator outputting a digital signal having one logical value during a time period between two adjacent spike voltages included in the output voltage; and a counter that counts the number of pulses of a clock in a period when the output of the comparator has one logical value.
摘要:
A method of manufacturing a purified product of a liquid medium-chain alkyl-modified polydimethylsiloxane that is free of a specific (unpleasant) odor and is practically odorless, the method comprising the steps of: [A] synthesizing a liquid medium-chain alkyl-modified polydimethylsiloxane by carrying out a hydrosilylation reaction between a hydrosilyl-containing polydimethylsiloxane and an α-olefin with 4 to 18 carbon atoms; and [B] subjecting a crude product of the liquid medium-chain alkyl-modified polydimethylsiloxane obtained in preceding step [A] to an odor-removing treatment by conducting a hydrogenation reaction which is carried out in the presence of a hydrogenation catalyst.
摘要:
In a hybrid IC including, a semiconductor chip including a capacitance sensor and a semiconductor chip including a detection circuit for detecting a variation in capacitance, the number of bonding wires required between the chips is reduced. A rear surface of a sensor chip is connected to an electrode on a surface of a support substrate on which the sensor chip is mounted. A potential at one terminal of a capacitor of a sensor is set at a reference potential. A pad of another terminal is formed on a surface of the sensor chip. A detection circuit chip includes: a pad to serve as a connection terminal of the capacitor; a bias circuit connected to a terminal, for outputting a bias voltage to charge the capacitor; and a detection circuit connected to the terminal through a capacitor, for detecting a variation in potential of the terminal of the capacitor as an electrical signal. The chips are interconnected through a bonding wire between the pad of the terminal and the pad of the terminal.
摘要:
A signal detection circuit comprising: a differential amplifier to which an output voltage of a detection coil of a magnetic sensor is to be applied; a comparator to output a digital signal being at one logic level in a period between two spike-shaped voltages adjacent to each other in the output voltage of the differential amplifier; and a count circuit to perform a count operation in a period during which the comparator outputs the digital signal of the one logic level, the count circuit including a first counter to count a first clock having a predetermined frequency, a second counter to count a second clock being equal in frequency to and different in phase from the first clock, the second counter having the same number of bits as the number of bits of the first counter, and an adder to add count values of the first and the second counter.